1. Field of the Invention
The present invention relates to a separator and a fuel cell having the separator.
2. Description of the Related Art
Fuel cells, which generate electricity through an electrochemical reaction between hydrogen and oxygen, are attracting attention as energy sources. A fuel cell has a stack structure in which membrane-electrode assemblies, each having an anode (hydrogen electrode) and a cathode (oxygen electrode) on both sides of an electrolyte membrane that has proton conductivity, and separators are stacked alternately (the fuel cell having such a stack structure is hereinafter referred to also as “fuel cell stack”).
JP-A 2004-6104 describes a separator having a fuel gas plate that faces an anode (hereinafter referred to as “anode facing plate”), an oxidant gas plate that faces a cathode (hereinafter referred to as “cathode facing plate”), and an intermediate plate disposed between these plates. In the separator, each gas plate has a through-hole and a gas communication hole, and the intermediate plate has a delivery passage for delivery of a fuel gas or an oxidant gas from the gas communication hole to the through-hole of each gas plate.
A load is applied to the fuel cell stack in the stacking direction of the stack structure, to prevent deterioration in cell performance due to an increase in contact resistance at any point in the stack structure and to prevent gas leakage.
In the separator described in JP-A-2004-6104, however, the delivery passage passes through the intermediate plate in the thickness direction, and thus the rigidity against the loads applied vertically with respect to the surface of the separator, that is, in the stacking direction of the stack structure, is relatively low at a portion of the intermediate plate where the gas delivery passage is formed.